Up top 100,000 rail commuters suffered travel chaos today as overrunning night engineering work halted services into mainline Waterloo station.
A second set of Network Rail (NR) overrunning engineering works in the Dorking and Epsom area added to the disruption.
Cancellations and late running and changes to the timetable will last most of the day.
Problems in the Waterloo area meant trains were unable to leave a number of depots and enter service.
When they did start running there were delays of an hour with cancellations and revised short notice changes to service.
Operator South Western Railway (SWR) told commuters tickets were being accepted on Great Western Railway (GWR) services between Basingstoke, Reading and Paddington.
Tickets are also being accepted on Southern Railway and London Underground between Waterloo, Richmond/Wimbledon and Paddington.
An NR spokesperson said: “We apologise to passengers for the disruption to services across the south western network this morning owing to a possession overrun. Disruption, including severe delays and cancellations, will last until the afternoon. Passengers should check with their train operator or visit www.nationalrail.co.uk before travelling.”
It came as it was revealed London commuters face the threat of more overruns and weekend closures over the next five years as NR spends a record £24 billion from April trying to sort out the daily chaos with track, signal and points faults a top priority.
But it means more overnight engineering work bringing with it the threat of it not finishing on time and hitting morning rush-hour services.
NR will announce next week more than £2b will be spent on maintenance and day to day upgrades on lines out of Waterloo; Southern, Southeastern and Thameslink will receive £4.5b of upgrades with a further £4.5b on routes to and from Paddington.